Answer
a) See the explanation
b) See the explanation.
Work Step by Step
a) A parametric curve is known to be parameterized in the plane if a pair of the coordinates on the curve (let us say $(x,y)$) are shown as the functions of a variable $t$.
b)
Let us take a curve with function $(x,y)$ represented as $x=a(t),y=b(t)$, where $t$ is a variable ; $t \in N$ (N=real numbers). Plot the points on the curve by calculating the values of $a(t)$ and $b(t)$ (as x,y pairs).